Gulf Stream Currents¶
An example that uses ipyleaflet to reproduce style of visualization used in the New York Times article In the Atlantic Ocean, Subtle Shifts Hint at Dramatic Dangers (March 2, 20121).
[1]:
from ipyleaflet import Map, TileLayer, basemaps
from ipyleaflet.velocity import Velocity
from intake import open_catalog
[2]:
cat = open_catalog("https://raw.githubusercontent.com/pangeo-data/pangeo-datastore/master/intake-catalogs/ocean.yaml")
ds = cat["sea_surface_height"].to_dask()
ds
[2]:
<xarray.Dataset>
Dimensions: (latitude: 720, longitude: 1440, nv: 2, time: 8901)
Coordinates:
crs int32 ...
lat_bnds (time, latitude, nv) float32 dask.array<chunksize=(5, 720, 2), meta=np.ndarray>
* latitude (latitude) float32 -89.88 -89.62 -89.38 ... 89.38 89.62 89.88
lon_bnds (longitude, nv) float32 dask.array<chunksize=(1440, 2), meta=np.ndarray>
* longitude (longitude) float32 0.125 0.375 0.625 0.875 ... 359.4 359.6 359.9
* nv (nv) int32 0 1
* time (time) datetime64[ns] 1993-01-01 1993-01-02 ... 2017-05-15
Data variables:
adt (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
err (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
sla (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
ugos (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
ugosa (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
vgos (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
vgosa (time, latitude, longitude) float64 dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
Attributes:
Conventions: CF-1.6
Metadata_Conventions: Unidata Dataset Discovery v1.0
cdm_data_type: Grid
comment: Sea Surface Height measured by Altimetry...
contact: servicedesk.cmems@mercator-ocean.eu
creator_email: servicedesk.cmems@mercator-ocean.eu
creator_name: CMEMS - Sea Level Thematic Assembly Center
creator_url: http://marine.copernicus.eu
date_created: 2014-02-26T16:09:13Z
date_issued: 2014-01-06T00:00:00Z
date_modified: 2015-11-10T19:42:51Z
geospatial_lat_max: 89.875
geospatial_lat_min: -89.875
geospatial_lat_resolution: 0.25
geospatial_lat_units: degrees_north
geospatial_lon_max: 359.875
geospatial_lon_min: 0.125
geospatial_lon_resolution: 0.25
geospatial_lon_units: degrees_east
geospatial_vertical_max: 0.0
geospatial_vertical_min: 0.0
geospatial_vertical_positive: down
geospatial_vertical_resolution: point
geospatial_vertical_units: m
history: 2014-02-26T16:09:13Z: created by DUACS D...
institution: CLS, CNES
keywords: Oceans > Ocean Topography > Sea Surface ...
keywords_vocabulary: NetCDF COARDS Climate and Forecast Stand...
license: http://marine.copernicus.eu/web/27-servi...
platform: ERS-1, Topex/Poseidon
processing_level: L4
product_version: 5.0
project: COPERNICUS MARINE ENVIRONMENT MONITORING...
references: http://marine.copernicus.eu
source: Altimetry measurements
ssalto_duacs_comment: The reference mission used for the altim...
standard_name_vocabulary: NetCDF Climate and Forecast (CF) Metadat...
summary: SSALTO/DUACS Delayed-Time Level-4 sea su...
time_coverage_duration: P1D
time_coverage_end: 1993-01-01T12:00:00Z
time_coverage_resolution: P1D
time_coverage_start: 1992-12-31T12:00:00Z
title: DT merged all satellites Global Ocean Gr...xarray.Dataset
- latitude: 720
- longitude: 1440
- nv: 2
- time: 8901
- crs()int32...
- comment :
- This is a container variable that describes the grid_mapping used by the data in this file. This variable does not contain any data; only information about the geographic coordinate system.
- grid_mapping_name :
- latitude_longitude
- inverse_flattening :
- 298.257
- semi_major_axis :
- 6378136.3
array(-2147483647, dtype=int32)
- lat_bnds(time, latitude, nv)float32dask.array<chunksize=(5, 720, 2), meta=np.ndarray>
- comment :
- latitude values at the north and south bounds of each pixel.
- units :
- degrees_north
Array Chunk Bytes 51.27 MB 28.80 kB Shape (8901, 720, 2) (5, 720, 2) Count 1782 Tasks 1781 Chunks Type float32 numpy.ndarray - latitude(latitude)float32-89.88 -89.62 ... 89.62 89.88
- axis :
- Y
- bounds :
- lat_bnds
- long_name :
- Latitude
- standard_name :
- latitude
- units :
- degrees_north
- valid_max :
- 89.875
- valid_min :
- -89.875
array([-89.875, -89.625, -89.375, ..., 89.375, 89.625, 89.875], dtype=float32) - lon_bnds(longitude, nv)float32dask.array<chunksize=(1440, 2), meta=np.ndarray>
- comment :
- longitude values at the west and east bounds of each pixel.
- units :
- degrees_east
Array Chunk Bytes 11.52 kB 11.52 kB Shape (1440, 2) (1440, 2) Count 2 Tasks 1 Chunks Type float32 numpy.ndarray - longitude(longitude)float320.125 0.375 0.625 ... 359.6 359.9
- axis :
- X
- bounds :
- lon_bnds
- long_name :
- Longitude
- standard_name :
- longitude
- units :
- degrees_east
- valid_max :
- 359.875
- valid_min :
- 0.125
array([1.25000e-01, 3.75000e-01, 6.25000e-01, ..., 3.59375e+02, 3.59625e+02, 3.59875e+02], dtype=float32) - nv(nv)int320 1
- comment :
- Vertex
- units :
- 1
array([0, 1], dtype=int32)
- time(time)datetime64[ns]1993-01-01 ... 2017-05-15
- axis :
- T
- long_name :
- Time
- standard_name :
- time
array(['1993-01-01T00:00:00.000000000', '1993-01-02T00:00:00.000000000', '1993-01-03T00:00:00.000000000', ..., '2017-05-13T00:00:00.000000000', '2017-05-14T00:00:00.000000000', '2017-05-15T00:00:00.000000000'], dtype='datetime64[ns]')
- adt(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- comment :
- The absolute dynamic topography is the sea surface height above geoid; the adt is obtained as follows: adt=sla+mdt where mdt is the mean dynamic topography; see the product user manual for details
- grid_mapping :
- crs
- long_name :
- Absolute dynamic topography
- standard_name :
- sea_surface_height_above_geoid
- units :
- m
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray - err(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- comment :
- The formal mapping error represents a purely theoretical mapping error. It mainly traduces errors induced by the constellation sampling capability and consistency with the spatial/temporal scales considered, as described in Le Traon et al (1998) or Ducet et al (2000)
- grid_mapping :
- crs
- long_name :
- Formal mapping error
- units :
- m
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray - sla(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- comment :
- The sea level anomaly is the sea surface height above mean sea surface; it is referenced to the [1993, 2012] period; see the product user manual for details
- grid_mapping :
- crs
- long_name :
- Sea level anomaly
- standard_name :
- sea_surface_height_above_sea_level
- units :
- m
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray - ugos(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- grid_mapping :
- crs
- long_name :
- Absolute geostrophic velocity: zonal component
- standard_name :
- surface_geostrophic_eastward_sea_water_velocity
- units :
- m/s
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray - ugosa(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- comment :
- The geostrophic velocity anomalies are referenced to the [1993, 2012] period
- grid_mapping :
- crs
- long_name :
- Geostrophic velocity anomalies: zonal component
- standard_name :
- surface_geostrophic_eastward_sea_water_velocity_assuming_sea_level_for_geoid
- units :
- m/s
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray - vgos(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- grid_mapping :
- crs
- long_name :
- Absolute geostrophic velocity: meridian component
- standard_name :
- surface_geostrophic_northward_sea_water_velocity
- units :
- m/s
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray - vgosa(time, latitude, longitude)float64dask.array<chunksize=(5, 720, 1440), meta=np.ndarray>
- comment :
- The geostrophic velocity anomalies are referenced to the [1993, 2012] period
- grid_mapping :
- crs
- long_name :
- Geostrophic velocity anomalies: meridian component
- standard_name :
- surface_geostrophic_northward_sea_water_velocity_assuming_sea_level_for_geoid
- units :
- m/s
Array Chunk Bytes 73.83 GB 41.47 MB Shape (8901, 720, 1440) (5, 720, 1440) Count 1782 Tasks 1781 Chunks Type float64 numpy.ndarray
- Conventions :
- CF-1.6
- Metadata_Conventions :
- Unidata Dataset Discovery v1.0
- cdm_data_type :
- Grid
- comment :
- Sea Surface Height measured by Altimetry and derived variables
- contact :
- servicedesk.cmems@mercator-ocean.eu
- creator_email :
- servicedesk.cmems@mercator-ocean.eu
- creator_name :
- CMEMS - Sea Level Thematic Assembly Center
- creator_url :
- http://marine.copernicus.eu
- date_created :
- 2014-02-26T16:09:13Z
- date_issued :
- 2014-01-06T00:00:00Z
- date_modified :
- 2015-11-10T19:42:51Z
- geospatial_lat_max :
- 89.875
- geospatial_lat_min :
- -89.875
- geospatial_lat_resolution :
- 0.25
- geospatial_lat_units :
- degrees_north
- geospatial_lon_max :
- 359.875
- geospatial_lon_min :
- 0.125
- geospatial_lon_resolution :
- 0.25
- geospatial_lon_units :
- degrees_east
- geospatial_vertical_max :
- 0.0
- geospatial_vertical_min :
- 0.0
- geospatial_vertical_positive :
- down
- geospatial_vertical_resolution :
- point
- geospatial_vertical_units :
- m
- history :
- 2014-02-26T16:09:13Z: created by DUACS DT - 2015-11-10T19:42:51Z: Change of some attributes - 2017-01-06 12:12:12Z: New format for CMEMSv3
- institution :
- CLS, CNES
- keywords :
- Oceans > Ocean Topography > Sea Surface Height
- keywords_vocabulary :
- NetCDF COARDS Climate and Forecast Standard Names
- license :
- http://marine.copernicus.eu/web/27-service-commitments-and-licence.php
- platform :
- ERS-1, Topex/Poseidon
- processing_level :
- L4
- product_version :
- 5.0
- project :
- COPERNICUS MARINE ENVIRONMENT MONITORING SERVICE (CMEMS)
- references :
- http://marine.copernicus.eu
- source :
- Altimetry measurements
- ssalto_duacs_comment :
- The reference mission used for the altimeter inter-calibration processing is Topex/Poseidon between 1993-01-01 and 2002-04-23, Jason-1 between 2002-04-24 and 2008-10-18, OSTM/Jason-2 since 2008-10-19.
- standard_name_vocabulary :
- NetCDF Climate and Forecast (CF) Metadata Convention Standard Name Table v37
- summary :
- SSALTO/DUACS Delayed-Time Level-4 sea surface height and derived variables measured by multi-satellite altimetry observations over Global Ocean.
- time_coverage_duration :
- P1D
- time_coverage_end :
- 1993-01-01T12:00:00Z
- time_coverage_resolution :
- P1D
- time_coverage_start :
- 1992-12-31T12:00:00Z
- title :
- DT merged all satellites Global Ocean Gridded SSALTO/DUACS Sea Surface Height L4 product and derived variables
[3]:
center = [35, -50]
zoom = 4
m = Map(center=center, zoom=zoom, interpolation='nearest', basemap=basemaps.Gaode.Satellite)
display_options = {
'velocityType': 'Global Wind',
'displayPosition': 'bottomleft',
'displayEmptyString': 'No wind data'
}
wind = Velocity(
data=ds.isel(time=-1),
zonal_speed='ugos', meridional_speed='vgos',
latitude_dimension='latitude', longitude_dimension='longitude',
velocity_scale=0.2, max_velocity=1,
display_options=display_options
)
m.add_layer(wind)
m